Lift mechanism affording independent manual adjustment and power actuation of separate tools



May 15, 1956 ug- 2,745,329

LIFT MECHANISM AFFORDING INDEPENDENT MANUAL. ADJUSTMENT AND POWERACTUATION OF SEPARATE TOOLS Filed June 29, 1951 3 Sheets-Sheet l M Q U 0Q ml May 15, 1956 BUHR 2,745,329

LIFT MECHANISM AFFORDING INDEPENDENT MANUAL ADJUSTMENT AND POWERACTUATION OF SEPARATE TOOLS 3 Sheets-Sheet 2 Filed June 29 1951\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\y\y\\\\v 5,WA-LU May 15, 1956 BUHR 2,745,329

LIFT MECHANISM AFFORDING INDEPENDENT MANUAL ADJUSTMENT AND POWERACTUATION OF SEPARATE TOOLS Filed June 29, 1951 3 Sheets-Sheet 3 UnitedStates Patent LIFT lVIECHANISM AFFQRDING INDEPENDENT MANUAL ADJUSTMENTAND PGWER ACTUA- TION 0F SEPARATE TOOLS August G. Buhr, La Crosse, Wis.,assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis.

Application June 29, 1951, Serial No. 234,296

4 Claims. (Cl. 9746.45)

This invention relates generally to agricultural implements and is moreparticularly concerned with those features of construction andcombination affecting the mounting and adustment of such implements.

Implements of the type now in general use usually include a plurality oftool frames or rigs operatively mounted in laterally spaced relationbeneath and/ or adjacent opposite sides of a suitable mobile structure,hereinafter referred to as a tractor. Frequently these frames or groupsthereof are supported for relative vertical movement, and in such casesare often provided with dual lift mechanisms operative to effectindependent vertical movement or adjustment of the frames or groups.Usually such mechanisms are independently actuated by hand and/or byseparate power devices to effect one or more of the followingadjustments: simultaneous movement of the frames into and out of workingposition, selective movement of either frame into and out of workingposition while the other frame is held in a nonworking position,independent adjustment of working depth, and movement of the frames tothe same transport height regardless of differences in depth adjustment.

Attempts have been made to effect these adjustments with mechanismsincorporating a single power device, but in general the constructionsheretofore devised have been entirely too complicated and expensive forpractical purposes. In addition, these heretofore devised constructionsare generally incapable of affording a relative or independent incrementadjustment of a plurality of tool rigs, particularly if the power deviceemployed is of the hydraulic ram type.

Accordingly, the present invention is directed toward and has as anobject the provision of an implement lift mechanism afiording asimplified and inexpensive construction which can be readily actuated bya single power device and is capable of efiecting all of theaforementioned adjustments, including a relative or independentincrement adjustment of a plurality of rigs.

Another object of this invention is the provision of an implement liftmechanism embodying a simplified combination of parts affording acompact structure requiring a minimum of space for attachment andoperation, and which can be readily attached to and removed from atractor with but little time and effort.

Still another object of the present invention is the provision of asimplified and compact lift mechanism which can be quickly attached to atractor and operated without interference with rear mounted tools, andwhich, if desired, may be left on the tractor without materiallydetracting from the utility of the latter.

A further object of this invention is concerned with the construction oflift mechanism components readily combinable to provide a simplified andcompact assembly inherently affording one or more of the aforementionedfunctions and advantages.

The foregoing and other objects and advantages inherent in an apparatusembodying the present invention will become readily apparent from aconsideration of the following disclosure of an illustrative embodiment.And, accordingly, the present invention may be considered as comprisingthe various features of construction and/or combination hereinafter moreparticularly pointed out the detailed description and appended claims,reference being had to the accompanying drawing, in which: i i

Fig. 1 is a side elevation of a tractor implement combin-ation embodyingthe invention, the near side a rear traction wheel being omitted andother parts being broken away for the sake of clarity;

Fig. 2 is an enlarged section taken on line IIII of Fig. 1 looking inthe direction indicated;

Fig. 3 is a plan view of the structure shown in Fig.

with both control levers shifted to their forward position in theinterest of clarity; Fig. 4 is an enlarged partial side view showing thcontrol levers of Fig. 1 adjusted to provide the maximum difference inthe positions of the lift arms disposed on opposite sides of the tractoras afforded by the pin and slot connection with the actuating ram, partsbeingbroken away for the sake of clarity;

Fig. 5 is a schematic view showing the relative positions of parts whenthe ground working tools on opposite sides of the tractor are adjustedto afford maximum ground penetration; i

Fig. 6 is another schematic view showing the relative repositioning ofthe parts effected by moving only one of the levers from the positionindicated in Fig. 5 to its rearmost position; and f I Fig. 7 is a Viewsimilar to Fig. 5 which shows the ground working tools on opposite sidesof the tractor raised to transport position as effected by a completeexpansion of the actuating ram. f

Referring particularly to Fig. 1, it will be seen that the tractorelement of the combination comprises a rear'axle housing 1 having itsopposite ends supported in a conventional manner on widely spaced groundengaging rear traction wheels 2, only one of which is shown, a torquetube structure 3 projecting forwardly from a central portion of housing1 to cylinder block 4, and a front pedestal support 6 conventionallymounting closely spaced dirigible' wheels 7. An operators seat orstation 8 is mounted on housing 1 in superimposed spaced relation'to acentral portion thereof and the steering mechanism includes a rearwardlyextending shaft 9 and a steering wheel 11 disposed within easy reach ofan operator seated at station In this connection it is to be understoodthat the tractor is also provided with the usual operator actuatedcontrols, of which only a clutch pedal 12 is shown. A generallyconventional rig mounting structure is de-' tachably carried by theforward portion of the tractor and comprises a frame member 13 whichextends transversely across the front of the tractor and has its centralportion removably rigidly secured in any known manner to a tractorcarried bracket 14. The near end of member 13 is supportingly connectedwith the outer portion of a transverse draft bar 16 which is rectangularin cross section and has its inner end terminally fixed'to aside frameelement 17, the latter being detachably fixedly secured to the near sideof the tractor in abutting relation thereto. In this connection, it isto be understood that although there are identical rig mountingstructures on opposite sides of the tractor, only the one on the nearside has been fully shown and described in the interest of simplicity. V

A cultivating rig 18 is secured to each draft bar16v for independentadjustment longitudinally thereof, each rig comprising a rigid frontsupport arm 19 depending from and attached to bar 16 by means of a clamp21, a gang beam 22 terminating at its forward end in a rigid upstandingpart 23, and a pair of parallel links- 24 and 26 pivotally unitingvertically spaced portions of arm Patented May 15, 1956 I 9'"a'ndupstanding part 23; A plurality of cultivating shovels-27 'are -suitablyattached to'beam "22 andeach rig may include a plant guard or shield 28having its forward end pivotally connected to arm 19 by means of a link?'25 fatta'ched to the pivot support for theforward" endoflower link-24,the rear-end of thisgua-rd-being prbvidedwith'anupstanding part29towhich is. attached a-supporting' chain '31.

' Fiomthe fo'regoingit shouldnow'be obvious that the rigs 18;oneonteachs'i'de of the; tractor, are supported fo'findepende'nttransverse adjustment along their re- -sjsetrtive draffbals16 and "forindependent vertical adjtisunent 'afforded by theparallellinkagesconnecting their arms19. with.their upstandingparts 23; Andsince .the

intermediate thev ends thereof. This mechanism .com-

prises fa fabricated structure including a rigid transverse supportingfrar'n'e '32,"?1 pair of similar right and left hand control leverassemblies 33 carried by opposite end portions pt-rrame 32',".'and avlift orrock shaft assembly 34 'ed'bjjthe aforementioned assemblies.

Frame3'2iiiclude's a pair of similar plate members 36 rigidly. removablysecured to torque tube 3 by bolts.37; Members; 36 are formed to extendlaterally outward from epposedjponions of torque tube 3, with eachmember presenting vertically depending from and rear marginal flanges38,. of which thecorresponding flanges on opposite sides of the tractorare disposed in lateral alignment.

, Alp'airof similar plate members 39' are rig'idl'y'removan secured 'tothe laterally aligned front and rear flanges 38 .by bolts 41. Theseplates 39 are thus positioned lto extend transversely beneath torquetube 3 in vertical paralle'l relation .to one another and laterallyoutward beyond members'36.

fCo'ntrol lever assemblies 33"each comprise a quadrant typefbracket'lzh'avingan opening 43 "through a lower portion thereof and having atoothed upper marginalportion I i lgenerallyconcentric with opening 1431Opposite marginalfporti'ons .of.brackets 42 are provided with-simi- 1hr;inturnedflanges 46 rigidly removably securedtoopposed end-portions ofplatemembers 39 by bolts 47'. The "brackets .42 are positioned onopposite. sides .of Ithe tractor in.parallel relation longitudinallythereof 'with' theirlopenings 43ldisposed in transverse alignmentimmediately beueath torque .tube'3.

A'control element or lever 48' is operatively associated with eachbracket-42 .and'comprises an. elongated flat bar'sec'tion having itslower portionrigidly terminally connected side! abutting relation to.an. upper portion o fia plate member .49, thelatter having an openingtherethi'ough which .-is aligned. with the opening 43in theassociatedbracket.42 and fixedly receives a tubular bearing This bearing is.in-longitudinal alignment with and extends snugly through theaopening43 onthe associatedbraclrettflythus affording. a fore-andaft swingingmovement-'ofzleve'r 48 relative .to the bracket. 'Lever 48 ispositioned; to extend upward. alongside the inner. face of bracket ,4 2and-is..provided with an outwardlyoifset fiitdQpar-LSZ having, avertically elongated opening .53 theret hrough operatively receiving thelower offset .end of aconnent'ional reciprocal latchrodfSAl. A .double:gear 56 is rotatably mounted between part 52 and .lever 48 withiheteeth on thelarger. gear. positioned .to receive the lower endofthelatchtrod therebetweenand with: the teeth-of.'the :smallergear. inmesh withthe underlying toothed. margin 44 of bracket 42. A moredetailed vdesoriptionno-fsthe.latch.mechanismis believed tobeunnecessaryfor acomplete understanding ofthe present invsnfi mentarylift shaft sections 57 and 58extendingoutwardfrom the left and rightsides of the tractor, respectively, as viewed by a person faced in thenormal direction of travel. A first line shaft section 57 includes atubular sleeve 59 rotatably journaled in the associated bearing 51 anddisposed thereby idcloseadjacent lower relation to .torque tube-3,- and,a second lift shaft sectionr58-in-r cludes a. tubular sleeve 61similarly journaledinthe other bearing 51. Sleeves 59 FandjGlxextend:inwardly from their respective bearingsil and the .opposed end portionsthereof .are disposed in proximate relation-.to one another adjacent theright side of the tractor. Round bar elements 62'. and63 extend=withinnandsarerigidly united, respectively, with sleeves 59.and.61 forrotation therewith. The laterally outer end portion of sleeve 59receives the laterally inner end portion of round bar element 62 and theremainder of this sleeve rotatably receives and further supportsa'portion of round hat-element -'63 which 'projects' inwardly throughand-beyond sleeve -61. It will be understood that sections '58 and: 57are coaxially aligned "and that sleeve 59 *and'round' bar element 62 maybe rotated relative to'sleeve-611ml roundbarelement 63. Round bar61611161118623111'63 extend laterally-outward beyond their respectivebear-- ings 51 and then forward generally at a right angle to theircommon transverse axis, these elements terminating: in'outwardlyprojecting similar left andrightside imple-, ment lift portions'66disposed in generally parallel relak tion to said axis. Similar anglesection-extensions67f are rigidlyremovably secured in any suitablemanner'tolift portions 66, these extensions'projecting transverselyoutward over the-gang beams 22' associated therewith, Each gang beam 22is operatively connected -'with'the associated'lift extension 67 bymeans of a'chain' or thelike 68,-the'rear ends of the plant guards beingalso-connected to these 'lift extensions by the aforementioned chains'31.

First'liftshaft section 57 has an implement :lift portion at one side ofthe tractor, the left side, and presents an'actuating arm '69 at theother side of the tractor. Second'lift shaft-section 58'has an implementlift portion. at the-"other side of the tractor, the right side, andpre-. sents'an-actuating arm 71 'at this other side. Actuating arms'69and '71are .similar to'eachother and are terminall'y rigidly secured, asby welding, respectively to: the end portion of sleeve 59"opposingsleeve61"and 'to a portion of sleeve 61 intermediate the ends thereof, beingnormally disposed, thereby to extend radially rear ward and downwardtherefrom in transverse alignment. Lower opposed portions of arms 69 and71 are provided with transversely aligned arcuate openings 72therethrough which are concentric with the longitudinal axis of shaft34. Apair of similar stop arms 73' and 74 are terminally rigidiy seemed,as by welding, respectively to sleeves 59" and-61 and are normallydisposed to extendradially rearward'and 'upward'therefrom in transversealignment and. adjacent the laterally inner ends :of bearings 51'forengagement with the inwardly extending stop projection 76on theassociated lever 48.

Any suitable power actuating device,.such as a single 'motion connectionbetween arms 69 and '71 .and Qtheram 75 7 7 Ram 77. receives fluid.underpressureefrom.asuit able pump 82 through a connecting conduit 83, theflow of fluid to and from the ram being controlled in a conventionalmanner by selectively moving a lever 84 to a position effecting thedesired result.

If desired, the tractor may be provided with a rear attached groundworking or other implement, indicated generally by numeral 86. Asillustrated, this rear attached implement is mounted for verticaladjustment by means of conventional draft links 87 and lift arms 88, thelatter being operatively connected with a power device shown generallyas the plunger 89 of a single acting ram 91. Pump 82 supplies ram 91with fluid under pressure through a connecting conduit 92, the flow offluid to and from this ram being also controlled, in the conventionalmanner previously indicated with respect to ram 77, by the actuation oflever 84. In this connection, it should be understood that the rams 77and 91 may be simultaneously expanded or contracted, as desired, by theselective actuation of lever 84, and that the particular means employedfor effecting such a control or operation is in no manner essential fora complete understanding of the present invention. Consequently, afurther description of such mechanism has been dispensed with as beingunnecessary.

When the ground working tools on opposite sides of the tractor areadjusted to aflFord maximum ground pen etration (refer to Fig. 5),control levers 48 are disposed in their extreme forward portionsrelative to the toothed portion 44 of bracket 42 and the hydraulic ram77 is in its fully retracted position. In order to simultaneouslyelevate the rigs on opposite sides of the tractor to transport position(refer to Fig. 7), the operator seated at station 8 moves lever 84 to aposition such that pump 82 delivers fluid under pressure to ram 77,whereupon plunger 78 moves forward to its fully extended position. Thisresults in a forward movement of extension 79 and pin 81, which in turncauses a limited rocking movement, clockwise as viewed in Fig. 1, ofshaft sections 57 and 58 about their common transverse axis.Consequently, stop arms 73 and 74 swing forward freely away from stops76, and lift portions 66 swing upward and elevate the rigs 18 by meansof the connecting lift chains 68. When only simultaneous movement of therigs on opposite sides of the tractor is contemplated, shaft sections 57and 58 may be united for rocking movement as a unit by inserting aremovable bolt means (not shown) through the pair of transverselyaligned openings 93 provided in arms 69 and 71 intermediate the endsthereof. The movement of the rigs to transport position as justdescribed is readily effected without shifting or adjusting thepositions of levers 48, simply by fully expanding ram 77.

Most hydraulic controls of the type herein indicated enable the operatorto partially expand or contract the ram or rams simply by placing thecontrol lever in a neutral or intermediate position, commonly calledhold position, terminating the admission or withdrawal of additionalfluid. However, it is extremely diflicult, if not impossible, to quicklymanipulate the control lever to effect increment adjustment as to theextent of soil penetration by the rig carried tools. Moreover, the valvemechanisms necessarily incorporated in such controls are subject toleakage which also makes it difficult to retain the implements in aselected position. In addition, the use of a single power actuatingdevice usually precludes effecting a relative or independent incrementadjustment of a plurality of tool rigs. These difliculties are entirelyovercome and the desired control effected simply by the provision of alift mechanism embodying parts constructed and combined for coaction ashereinbefore described. This phase of the operation is quite simple andcan be readily effected with a minimum of effort.

For example, assuming the tool rigs are in their transport positionshown in Fig. 7, the first step is to move both levers 48 to theirextreme rearward position rela tive to the toothed portion 44 of bracket42. This can be done with but little effort as such movement of theselevers fails to bring the stops 76 thereon into engagement with arms 73and 74. When this has been done, a movement of control lever 84 to aposition permitting flow of fluid from or out of ram 77 enables theweight of the raised implements to effect a collapse or contraction ofthe ram to an extent determined by the engagement of arms 73 and 74 withthe stop 76 on the associated lever 48. This places the cultivatingshovels of both rigs 18 slightly above the ground generally in theposition shown for the uppermost shovel in Fig. 6. Under theseconditions, either rig may be further lowered relative to the other anextent limited by the effective length of the arcuate opening 72 in theassociated actuating arm, i. e. arm 69 or 71. The limit of thisrelativelowering movement is clearly shown in Fig. 6 by the vertical spacing ofthe shovels 27 and the angular displacement of lift arm portions 62 and63. Obviously, the rearmost lever 48 can now be independently moved toits foremost limiting position relative to its toothed quadrantpossition 44, that is, to the position shown in Fig. 5 which places theshovels on the associated rig in their lowermost position.Alternatively, any movement of the rearmost control lever toward itsforemost position permits a corresponding relative forward movement ofthe other lever, i. e. a relative lowering movement of the shovelscontrolled thereby.

In this connection, the use of a double gear latch mechanism embodyinggear elements having a difference in diameters of the order shownaffords a relative or simultaneous increment adjustment of the tool rigs18 with a minimum movement of levers 48 and with a toothed quadrant ofpractical size. Moreover, once the stop arms 73 and 74 are engaged withthe stops 76 on the associated levers 48, the latter may be movedseparately or together toward their rearmost limiting positions toefiect either a relative or simultaneous raising of the tool rigs. Ofcourse, the extent of relative raising movement is limited by theeffective length of the arcuate slots 72 as previously mentioned withrespect to a relative lowering of the rigs. In addition, when the rigsare in a lowered position such that the rearmost lever 48 is forward ofits rearward limit, a further rearward actuation of this lever willeffect a raising movement of both rigs providing the forward angulardisplacement of the other lever is such (note Fig. 4) that pin 81engages the rear end of the slot 72 in arm 71 and the forward end of theslot 72 in arm 69 before the actuated lever reaches its rearmostposition. Of course, such a simultaneous raising of both rigs effects anexpansion of ram 77, which produces a resisting vacuum within the ramcylinder that must be overcome by the force manually applied to theactuating lever 48.

Consequently, with the parts positioned as shown in Fig. 5, either lever48 may be manually moved to its extreme rearward position which willfirst eifect a relative raising of the associated rig followed by asimultaneous movement of the arms 69, 71 and both rigs to the relativepositions indicated in Fig. 6. During this movement, the nonactuatedlever will remain in its foremost position by reason of the engagementof its latch element 54 with the associated double gear 56. Obviously,the actuating lever will eflect the same relative movement and a lesserextent of simultaneous movement if it is shifted from its position shownin Fig. 5 to some position intermediate the angular displacement of thelevers shown in Fig. 6. Similarly, the extent of the initial relativemovement depends upon the relative angular displacement of the levers48, i. e. there would be no initial relative movement with the maximumangular displacement of the levers shown in Fig. 4 and a maximum initialrelative movement with no angular displacement as shown in Fig. 5.

amazes.

Furthermore; regardlesssofs the posit ons o the l vers 48,52 .movmentaof: con roller/c1184, to itsram expandin position, results/in asimultaneous movement of both rigs to-theisame height, thatis, to.the,transport position.

settingof lift levers 48. Also, whenthuslowered, levers- 48 m y: be s maneously or ndependently actuate o.

effect increment vertical, adjustment of'onepr both-rigs,

and therefore the depth of soilpenetration, as desired.

In-,this -connection,-it should also be apparent that the extent towhich the'rigs and plantguards can .be raised or :lowered by theactuation of lovers 48 may be furthe! varied by changing the efiective-length; of thejift chains 68 and.31. For example, with the tool rigsand shieldsvresting on top of the ground, these chains can bedisconnected, the levers 48 shifted to either raise or. lower the liftarms 66 relative tothe rigsand guards, and

thechains reconnected.

If desired, the implement may be readily removed from the tractor in theusual manner and without materially affecting the lift mechanism, simplyby first lowering the implement to the ground and then; removing thelift armextensions-67 to which the chains 31 and 68 are connected. Thisleaves the lift mechanism suhstantialiy intact, and the mounting andcompactness of thelatter permits the tractor to. be effectively andeffioiently used on other jobs,.as desired. Moreover, this liftmechanismin-no-manner hindersor interferes with the mounting andoperation-of rear attached tools or'other apparatus supported on orcoupled -to the rear of thev tractor.-

Neither does this lift mechanism present any obstructionto-the-visibility of an operator seated at, station 8.

In the event it is desired to also remove the lift mochanism fromthetractor, this can bereadily done, assuming the implement has alreadybeen removed as described, simply by-disconnectingextension 79 from ramplunger 78, and. then removing thestuds 37 securing frame member-5.36mtorque tube 3, whereupon theentire lift mechanismmaybe lowered to theground. If 'both-theimplementand lift mechanism are to be removedat-the-same time; lift arm extensions67 need not; be removed from theportions 66, as all that is necessary is to separatethe implementfromthe lift mechanism by disconnecting the chain&:31,and-68. Obviously,the lift mechanism maybe. just as readily reattached to the tractorsimply byreversing theprocedure described for detaching.

Inviewof the foregoing, it should now-be obvious that a lift mechanismconstructed and mounted .in accordance with the teachings-hereindisclosed is inherently capable of .afiording the improved results .andadvantages previously-mentioned or discussed. Also, it should-beapparenLthat themechanism disclosed is applicable to tractors other thanthose of the torque tube type. Consequently, it, is: to beunderstoodthat it is notintended ns. s rus re tor-adjud ed mut n the lete w ser sis... itslasspq a ed zbea ip suprqrt nd. elati e IQ fi er .1 etio i-. s pnqu d meow; a d S p ort flash-P ow an arcuate gear segmentdisposed inspaced. cone f, relation respect to the .axis of rotation, ofsaid ,shaft sections,.a double gearcarried by each lever for rotation.relativethereto. and presenting atoothed periphery adjacentsaidlever-inmesh with said arcuatesegment of. theassociatedsupport and atoothed periphery Qflarger, diameter disposed. in partially overlappingrelation to the side of the support remote from the associated lever areciprocable element carried by said lever in position for selectivelatching engagement with said toothed p riphery oflarger diameter, saidshaft sectionseach pro-.1. senting..a.radially oi fset lift portion,radially extending actuating arms disposed in proximate side opposedrela-j' tion to. each other on said.;shaf t sections, respectively, a;stop projection secured toeach shaft section and a larly spaced from itsassociated actuating arm and d posed adjacent the associated controllever, a stop .ele}. ment carried by each control lever and positionedthereby; forengagement with the stop projection on the associated shaftsection, .anda removable meansuun iting said actuating arms forsimultaneous movement, said actuating arms having transversely, aligned.arcuate slots adapted for connection with an actuating device andbeingoperative when said, arms are united to afford a limited movement;ofsaid actuating arms relative to said device, and operativc, whensaidarm uniting means -is removed, to also. afford alimited movement ofsaid arms relative toeach. other.

An. risu tun lm qh 7 mp i n amio tion; atractorhaving a rearwardoperators muting, pair ofjmplernent framesrnounted at opposite meter isaid tractor forwardly of, said operators station for ad-l justmentindependently of each other between implement raised and. implementlowered positions, a bracket structure mounted on said tractorforwardlyof said op erators station, a first lift shaft sectionrotatably sup-.

ported insaid bracket structure on an axis extending, transversely of.said tractor and having. an implement lift; portionoperatively'connected with one of said implement] frames at one side vof saidtractor, and presenting an ac tuating .arm at the other side of saidtractor; a second. lift shaft section. rotatably supported I in saidbracketi structure coaxiallywith said first liftshaft section and:having an actuating'arm at said other side of said tractor andpresentingan implement lift portion operatively coi nected with theother of said implement frames. at sa id other side of ,saidtractor;said actuating arrns extending, radially from said liftshaft sections inproximity ,to eac hl other at said other side of said tractor; a pair ofrelatively rotatable control elements pivotally mounted, respectively,on said lift shaft sections, each of saidlift sh aft sections and itsassociated control element presentin g'l adjacent portionscoactablewitheach other to selectively; determine limit positions to which said liftshaft seniors; can be rotatedrelative to their associated .control ele-Imerits in implement lowering direction, and a single. actuating deviceconnected with said actuating arms at.

' said other side of said .tractorand operative to rotatesaid.

lift shaft. sections in. implement raising direction and permittinglimited rotationof eachof said liftshaft sec tions relativeto each otherin implement loweringidii rection.

3. An agricultura implement as setforthinclaim 2. andfurther comprisingtubular bearing elements rigidly secured, respectively, to said controlelementsv and rQ-l tatably, connected in supporting relation,respectively,

it a t h ft c pns and m an a ah y mount: nsa d arinsl me t n id b as ttucture An u u l mpl m as s t t nc a m. 2; in which said coactableadjacent portions of each of; aid, lift h t y e t pu iandsas pciedfiqntm ;s1. an -som pr es a tmrwisqi n. x endin J d ly 9 said liftReferences Cited in the file of this patent UNITED STATES PATENTSCarlson Apr. 28, 1931 Strandlund Aug. 15, 1933 Strasser et a1 Apr. 16,1940 10 Silver July 22, 1941 Cutt Mar. 16, 1943 Silver May 25, 1943Hipple July 20, 1943 Smith Aug. 24, 1943 Brown May 29, 1945 Silver Aug.26, 1947 Baade Sept. 2, 1947

